Fused electrical connector



Oct. 14, 1952 J. F. CONRAD FUSED ELECTRICAL CONNECTOR Jet Filed Oct. 26,1950 w r M2 M WM R VC 0 r m w J Patented Oct. 14, 1952 FUSED ELECTRICALCONNECTOR John F. Conrad, Ebensburg, Pa., assignor to Deltron ElectricProducts, Inc., Ebensburg, corporation of Pennsylvania Pa., a

Application October 26, 1950, Serial No. 192,259

2 Claims. 1

This invention relates to electrical connectors, and more particularlyto connectors of the fused type for use in connection with electricalcables, the device having some features in common with my copendingapplication Serial No. 193,176, filed October 31, 1950.

One object of my invention is to provide a connector of the type whichincludes a cartridge fuse, wherein the cable ends are more firmly heldand more accurately centralized in the fuse holder than in variouspreviously known connectors of this general type.

Another object of my invention is to provide a fused connector whereinthe parts within the holder are readily accessible, but are,nevertheless, maintained in assembled position with suflicient firmnessto avoid loose electrical connections and consequent faulty conductivityand other damage during handling of the device.

As shown in the accompanying drawing, Figure 1 is a longitudinalsectional view through the connector; Fig. 2 is a view taken on the lineII--II of Fig. 1; Fig. 3 shows a modification of the anchoring devicefor the cable at one of the fuseholding sockets, and Fig. 4 is asectional view through the structure of Fig. 3.

Referring first to Figs. 1 and 2, the fuse structure is employed toconnect ends 6 and l of a sheathed cable. The connector comprises atubular body member 8 that is of insulating material and suitably may beof a fibrous nature combined with phenolic resin or the like, under highpressure, to give it good mechanical strength.

At one end, a knurled seating member ID suitably of aluminum has tightpress fit with the tube 8 and is covered at its outer side by a gasketll of rubber or other insulating material that is pressed into place.The wire strands of the cable extend through a gland l2 and a collar 13and are mushroomed or frayed out at M. A fuse socket 15 that is axiallysplit for yieldability, has an outwardly-extended tubular portion [6with which the gland l2 has threaded engagement. The gland 12, whenscrewed tightly into place, will cause the collar l3 to clamp the wiresagainst the end wall I! of the extension 16.

In making the assembly, the tube 8 will be slid along the cable end 6,so as to render the bared wires accessible for these coupling members,at the other end of the tube. The wall I! is dished somewhat, so thatwhen the gland I2 is screwed home tightly, the cable will be centralizedwith respect to the axial line of the bushing II. The parts l2, l3 and Imay suitably be of brass.

At its other end, the tube has a knurled bushing 18, suitably of brass,firmly held therein, and there is a cap-like extension 19 of the samematerial as the tube 8, which has a brass bushing 2| firmly heldtherein, the two bushings being internally threaded for engagement witha coupling member 22 of brass that has a split socket 23 and anoutwardly-extending tubular portion 24 whose end wall is concave. Aninsulating bushing 25 is snugly held in the outer end of the cap 19.

In assembling the parts, with the coupling 22 removed from the cap 19,the cable end I is threaded through the bushing 25, through a gland 26and a collar 27 that will centralize the cable end on the concave seatin 22. The cable ends are frayed or mushroomed at 28, and the gland 26is screwed to clamp the collar 21 against the wires. The cap 19 is thenslid along the cable and turned to screw its bushing 2| on tothe'extension 24 of the coupling member 22, and the coupling member 22is screwed into the bushing [8, if it has not previously been screwedinto place.

A cartridge fuse 30 of a standard form, having the usual metal caps 31and 32 engageable in the sockets I5 and 23 respectively, is electricallyconnected to the end wall of the socket 23 by laminated fiat conductorstrips 33 that are riveted at the ends to dies 34 and 35, the rivetspreferably being of copper. A spring 36 holds the brass discs 34-35tightly to their seats and also urges the cartridge into its socket 15to thereby hold the end of the cap 3| snugly against the bottom wall ofthe socket l5 and thus provides for better conductivity than that whichwould be afforded simply by the split sides or fingers of the socket.The spring therefore maintains the electrically conductive parts underpressure and avoids looseness developing during use and handling of thedevice.

The use of copper rivets for connecting the discs 34-35 to the conductorstrips 33 insures better maintenance of electrical connection than ispossible with bolts or soldering. Where bolts or screws are used, thereis danger of looseness through careless assembly, of occurring duringuse, while where a solder is used, it has a low melting point ascompared to copper or brass and the solder would sometimes soften beforeor when the fuse reaches a rupturing temperature. Furthermore, copperrivets will usually be employed because of their high conductivity,Whereas in the case of screws, they are commonly made of brass becauseof better machineability but which is not so conductive as copper.

The laminated conductor strips 33 are advantageous, because not only canthey be made of sufiicient length to allow for some extension andretraction, but they provide large total conductive and heat-radiatingarea and therefore will not develop heat in the confined space to suchan extent as to cause the fuse to be ruptured at lower amperage ortemperature than that for which the fuse is designed.

A modified form of cable-anchoring device is shown in Figs. 3 and 4. Inthis case, the gland [2a corresponds somewhat to the gland [2 but islengthened to provide for a set screw 49 which is turned into the glandto deflector bend thecable, thus holding it more securely than at [4, orsubplementing the clamping arrangement at M.

I claim as my invention:

1. An electrical connector comprising a tubular body member ofinsulating materialhaving an insulating apertured closure member at oneend, to receive a cable end, *aconductive eeble-holding de'vice'at theinner side of theclosure member and having a conductive socket toreceive one end of afuse cartridge, a threaded bushing rigidly se- "cured within the body member at its other'end, a tubular cap member ofinsulating material engageable with said other end of the body member,and having a central hole for a cable, a

threaded bushing rigidly secured within the cap member, a couplingmember that is exteriorly threaded for connecting the two bushings andis centrally recessed inits inner' end to serve as a cartridge-receivingsocket and having a threaded recess in its outer end, alined with thehole in the cap and an eXteriorly-thre aded gland engage-able with thewall oftherecess to clamp a cable agains't the innerend wall of thisrecess,

the coupling member and the gland being of conductive material. I V w H2. Anel'ectrical connector comprising a tubular body member ofinsulating material having an insulating apertured closure member at oneend, to receive a cable end, a conductive cableholding device at theinner side of the closure member and having a conductive socket toreceive one end of a fuse cartridge, a threaded bushing rigidly securedwithin the body member at its other end, a tubular cap member ofinsulating material engageable with said other end of the body member,and having a central hole for a cable, a threaded bushing rigidlysecured within the cap member, a coupling member that is exteriorlythreaded for connecting the two bushings and is centrally recessed inits inner end to serve as a cartridge-receiving socket, the recessedportion being of reduced wall thickness and of smaller outside diameterthan the threaded portion and being split longitudinally, to serve as afuse-receiving socket, the outer end of the coupling member beingcentrally recessed and threaded for engagement with a gland that iscentrally apertured 'to receive a'cable that extends through the hole inthe cap and clamp the same against the end wall of this recess, thecoupling member beingof conductive material.

JOHN F. CONRAD.

REFERENCES CITED The following references are'of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,662,055 Chandler Mar. 13,19281,679,142 Wyman July 31, 1928 1,746,650 Harrington Feb. 11, 19301,822,883 Chandler; Sept. 15, 1931 2,419,152 'Mosebaoh Apr.-l5, 19472,466,997 Morris Apr. 12, 1949 2,475,352 Conrad- July 5, 1949

